lenses

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Pj
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Real name: Pavan Deep Singh
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lenses

Post by Pj » Fri Aug 04, 2017 11:13 am

Probably a naive question, but can I use a Micro Four Thirds lens on a C mount camera? Obviously I'll need an adapter. Are there adapters out there? There seem to be quite a few adapters allowing users to use the smaller C mount lenses on their MFT's cameras but not the other way around, surely there must be some out there. How much bigger is the APS-C sensor than Super 16? What focal length will a 12mm MFT lens give me on Super 16?


Pav

Krasnogorskistan
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Real name: Ed McDonald

Re: lenses

Post by Krasnogorskistan » Fri Aug 04, 2017 1:01 pm

Hi Pav,

They key here is flange focus distance (FFD)....

When the M4/3 system was designed, (and why it has proved so popular) was their choice of a really short FFD, thus allowing lenses from virtually all previous systems (with 'larger' / 'longer' FFD) to be able to be fitted with an adapter, which the Chinese willingly obliged us with, so long as the FFD was longer than the M4/3 distance (and very exceptionally, even where the FFD of the lens' original system was shorter), as generally speaking, anything with a shorter FFD isn't going to 'work' (within acceptable limits), and no commercial mount will be available.

Check out this table:

https://en.wikipedia.org/wiki/Flange_focal_distance

As you can see from the linky, the distance they chose, while very short, was actually longer than the C mount spec, so I think your question is perfectly valid. This means that theoretically speaking, a C - to M4/3 is possible, as the M4/3 mount is 1.7mm longer, but probably due to lack of demand or, more likely, the very real technical restrictions on creating such a mount within the space available, I am not aware that any have actually been produced: the mount 'locking' system necessarily has itself got to fit on the camera side of the mount, 'behind' the M4/3 lens mounting flange (where the distance itself is calculated from), and this is exactly where your C mount threads, and any other associated bits of the camera body sit themselves....

From the other side of the equation, the M4/3 mount length hasnt stopped M4/3 users adapting C and other shorter mount lenses to their cameras, as they have the advantage of in-camera digital zooming which overcomes some of the focus / vignetting problems when using a lens with a shorter FFD than the design requires..

Although there are some very good lenses made 'natively' for M4/3, the very slight issue of not being able to use these has to my mind been massively outweighed by the ability now to find very cheap adapters to be able to use virtually ANY lens on a c-mount camera.......and don't forget you can string adapters together too.... although this silver lining is of course, in some senses outweighed by the price that 'old glass' now attracts from all the new digital users, and the fact that new cameras are once again being made in C mount....

Pic attached shows my Alpha 16 sporting an East German PB mount zoom courtesy of a couple of Canon adapters.....

Hope this helps....
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Pj
Posts: 298
Joined: Fri Nov 28, 2003 12:52 am
Real name: Pavan Deep Singh
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Re: lenses

Post by Pj » Sat Aug 05, 2017 4:01 pm

Thank you, you've explained that really, I hadn't thought about the MFT lens mount which sticks out more than 1.7 and wouldn't let the MFT lens fit the C mount camera.

Pav

Krasnogorskistan
Posts: 22
Joined: Wed Mar 01, 2017 2:36 pm
Real name: Ed McDonald

Re: lenses

Post by Krasnogorskistan » Sat Aug 05, 2017 8:04 pm

Modern digital systems are also throwing up some interesting lenses which can be adapted to our film cameras, even if not in the mount we've been talking about so far...

I've liked what Voigtlander have been doing for a while with their low-light offerings, but I would love to see results from their latest wides on 16mm. The Voigtlander Hyper-Heliar is available in Leica M mount as a 10mm rectilinear (adding to a range which already includes a 12 and a 15). Very very slow at a maximum aperture of f5.6 and probably quite limited because of this, its pricey too, but finding quality wide angle lenses that will go to super16 isnt particularly easy either.....

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